Effect of glucose on the expression of the angiotensinogen gene in opossum kidney cells.
To investigate whether D(+)-glucose has a stimulatory effect on the expression of the angiotensinogen (Ang) gene in opossum kidney (OK) cells, we used OK cells with a fusion gene containing various lengths of the 5'-flanking regulatory sequence of the rat Ang gene fused with the human growth hormone (hGH) gene as a reporter, stably integrated into their genomes. The level of expression of the fusion gene was quantified by the amount of immunoreactive-human growth hormone (IR-hGH) secreted into the medium. The addition of D(+)-glucose stimulated the expression of pOGH (Ang N-1498/+18) in OK 27 cells in a dose-dependent manner (5 to 25 mM), whereas the addition of D-mannitol, L-glucose and 2-deoxy-D-glucose (25 mM) had no effect. The stimulatory effect of D(+)-glucose (25 mM) was blocked by the presence of staurosporine or H7 (an inhibitor of protein kinase C) or U73122 (an inhibitor of phospholipase C and A2) but not blocked by the presence of Rp-cAMP (an inhibitor of cAMP-dependent protein kinase A). The addition of D(+)-glucose (25 mM) also stimulated the expression of pOGH (Ang N-960/+18) and pOGH (Ang N-688/+18) in OK 960 and OK 688 cells, respectively. It had no stimulatory effect, however, on the expression of pOGH (Ang N-280/+18) and pOGH (Ang N-35/+18) in OK 280 and OK 35 cells, respectively. The addition of D(+)-glucose also had no effect on the expression of pTKGH in OK 13 cells, an OK cell line, into which had been stably integrated a fusion gene, pTKGH containing the promoter/enhancer DNA sequence of the viral thymidine-kinase (TK) gene fused with a human growth hormone gene as a reporter. These studies demonstrate that the stimulatory effect of high D(+)-glucose concentration (25 mM) on the expression of the angiotensinogen-growth hormone fusion genes in OK cells is mediated via the 5'-flanking region of the angiotensinogen gene and the protein kinase C signal transduction pathway. Our data indicate that a high glucose concentration may activate the renin-angiotensin system in the renal proximal tubular cells.
Wang
T T
TT
University of Montreal, Maisonneuve-Rosemont Hospital, Research Center, Quebec, Canada.
Wu
X H
XH
Zhang
S L
SL
Chan
J S
JS
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D000804:Angiotensin II / Q000235:genetics*; D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology; D002273:Carcinogens / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D003847:Deoxyglucose / Q000494:pharmacology; D004234:Diuretics, Osmotic / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects*; D005947:Glucose / Q000494:pharmacology*; D013006:Growth Hormone / Q000235:genetics; D007668:Kidney / Q000166:cytology; D008353:Mannitol / Q000494:pharmacology; D009893:Opossums; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D011760:Pyrrolidinones / Q000494:pharmacology; D011994:Recombinant Proteins / Q000235:genetics; D019311:Staurosporine / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors
D000963:Antimetabolites; D002273:Carcinogens; D004234:Diuretics, Osmotic; D004791:Enzyme Inhibitors; D004963:Estrenes; D010726:Phosphodiesterase Inhibitors; D011760:Pyrrolidinones; D011994:Recombinant Proteins; D013873:Thionucleotides; D000804:Angiotensin II; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; C016957:adenosine-3',5'-cyclic phosphorothioate; D008353:Mannitol; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D013006:Growth Hormone; D003847:Deoxyglucose; D000242:Cyclic AMP; D010741:Phospholipases A; D010738:Type C Phospholipases; D019311:Staurosporine; D005947:Glucose; D013755:Tetradecanoylphorbol Acetate